30 March 2012

FT-817 on Mac OSX Leopard, via Bluetooth

I am not a MAC user, but I wanted to test the FT-817 CAT-to-Bluetooth adapter on it.

I borrowed a PowerBook G4 with OSX 10.5.8. Then I searched for a CAT software, and the easier to install was flrig from the fldigi suite. I tried jLog but it complained that "radiocomm.jar are not properly installed" (no results on Google to help troubleshooting). And I could not compile grig either.

I attach seven screenshots of the pairing procedure and sample usage. firig was able to control my FT-817 through the serial port over bluetooth, I just had to use the proper configuration (see the 6th screenshot below).

Provided there is software for more recent MACs, the adapter should work on them too.

Make sure to select the last option, "Any device"

flrig in use and the configuration screen

When you're done, disconnect the adapter

21 March 2012

Yaesu CAT bluetooth interface - video

For the Curious and the Interested, here is a short video introducing the wireless (Bluetooth) CAT interface I made for Yaesu FT-817/FT-857&FT-897:

Contact me if you want one interface for your shack.

13 March 2012

Frequency Reader with Tuning Knob

The "Frequency Reader" is a stand-alone display with three push buttons that allows to read remotely the FT-817 display data and gives minimal user interaction ability. It is supposed to work on FT-857 and FT-897 too.

As of today, March 13th 2012, the "Frequency Reader" supports a tuning knob which lets you retune the radio remotely. The firmware has been tailored for users of microwave transverters, but nothing prevents using it for the usual V/U/HF operations. Three buttons do:
  • USB/CW mode toggle (no action if in a different mode)
  • VFO A/B toggle
  • tuning step selection
Tuning step is selected using the F.R. knob and reminds FT-817 internal steps.

For interested builders, it should be noted that this new firmware works on a slightly different hardware circuit, on which few connections have been moved around to facilitate the design of PCB.

If a simple Frequency Reader is needed, just omit mounting the knob and step button leaving their terminals open.

Technical insight.
The Frequency Reader polls the radio every second for a frequency change, in case the operator touches the front panel dial knob. If the external knob is rotated, the VFO frequency is updated of a "step" amount every 100 ms. If the knob is rotated very fast, the step is increased accordingly in a linear fashion, allowing faster QSY's.

The knob component, a quadrature rotary encoder, must be selected with care. It should have no detents, or generate one step per detent. If it includes a pushbutton, it can be wired to any of the three required buttons mentioned above.

What is left to do.
  • Shoot a short demo video
  • Update the website with the new diagram and firmware
  • Refine the firmware for general public release

07 March 2012

A coil or a lifelong supply of enameled wire

While the supercapacitor and white LED in the handshake flashlight have been used to build a proof-of-concept USB rechargeable flashlight, the coil is now calling for attention. A passive audio filter came to my mind.

On my DVM the coil measures ~22mH for 100 ohm of wire resistance. At 1kHz this means a coil Q of 1,3 (Q = 2 * pi * f * H / R).

I am not into passive audio filters but the Q sounds too low to be useful. The other option would be to use the coil as a lifelong source of enameled copper wire. According to the perceived diameter (not measured, but it is thin) I would have about 1km of wire!